In cable modem applications, the cable modem needs to scan downstream RF channels and acquire valid channels that are allocated for such operations. The speed of this scanning and acquisition operation is important for the provider of the cable modem services, since it is directly related to the quality of service offered to the customers by the provider. The speed of this operation varies widely in relation to the specific scanning and acquisition methods or algorithms that are used. Therefore, the development of fast methods and algorithms for such operations is a competitive advantage in the cable modem marketplace.
Known methods for channel scanning and acquisition are quite slow. Currently available cable modems can take up to five minutes for a complete scanning and acquisition cycle. Often, channels are scanned in a “brute force” manner, wherein time is spent seeking to acquire each possible channel and each channel is treated in the same manner. The problem is exacerbated in Europe, where the number of possible channels is much larger than in North America.